60°N · February 15 — noon altitude 16.72°, daylight 8 h 47 min
At 60°N · February 15 the noon sun stands 16.72° above the horizon and the day runs 8 h 47 min. That altitude is 90° − |latitude − declination| with a declination of -13.28° for the date, and the times are apparent solar time — no refraction, no equation of time.
- Latitude
- 60°N
- Date
- February 15
- Day of the year
- 46
- Declination
- -13.28°
- Noon altitude
- 16.72°
- Sun at noon
- To the south
- Length of day
- 8 h 47 min
- Sunrise and sunset
- 07:37 – 16:23
- Half-day angle
- 65.86°
- Shadow of a 1 m pole
- 3.33 m
Times are apparent solar time, with noon set to 12:00 when the sun crosses the meridian.
A shadow is the tangent of the altitude, read backwards
If the noon altitude is h, a pole 1 m tall casts 1 ÷ tan h metres of shadow. Measure the shadow instead and the altitude falls out, and from the altitude you can work back to a date or a latitude — that is how Eratosthenes measured the earth in antiquity. Shadows stretch fast as the sun drops: at 45° the shadow equals the height, at 30° it is 1.7 times as long, and at 5° more than eleven times.
- 1 m ÷ tan 16.72°3.33 m
What this leaves out
Sunrise here means the centre of the sun crossing the geometric horizon, an altitude of 0°. The usual convention adds refraction and the sun’s own radius and uses −0.833°, which makes the day 8 to 10 minutes longer at mid-latitudes. The clock is apparent solar time: to reach civil time you still have to add the equation of time (±16 minutes), the gap between your longitude and your time zone, and any summer time. The declination formula carries an error of up to 1.5°, leap years are not counted, so dates after February sit one day out, and neither the observer’s elevation nor hills and buildings on the horizon are in here.
A high sun is a strong sun
The higher the sun, the less air its light passes through, and the stronger the ultraviolet. As a rule of thumb, when your shadow is shorter than you are, the ultraviolet is near its peak for the day — how long skin lasts before it reddens depends on the index and the skin type.
See burn times by UV indexNearby cells
Same latitude, other dates
Same date, other latitudes
Worth knowing
- Declination δ = 23.44° × sin(360° × (284 + N) ÷ 365), where N counts the days from 1 January.
- Noon altitude = 90° − |latitude − declination|; at the June solstice that is 90° − φ + 23.44° in the north.
- Length of day = 2H ÷ 15 hours with cos H = −tan(latitude) × tan(declination); beyond |cos H| = 1 lies polar day or night.
- Shadow = height ÷ tan(altitude). Times are apparent solar time, with refraction and the equation of time left out.
Common questions
Q. How high is the noon sun at 60°N · February 15?
16.72° above the horizon. That is 90° − |latitude − declination|, with a declination of -13.28° that day, and the day itself runs 8 h 47 min.
Q. How long is the day at 60°N · February 15?
8 h 47 min. In solar time the sun rises at 07:37 and sets at 16:23, and the half-day angle is 65.86°.
Q. How long is the noon shadow?
A 1 m pole casts 3.33 m at noon. It is 1 ÷ tan 16.72°, so multiplying the shadow by the tangent of the altitude gives the 1 m back.